Razlike u kohortnom fertilitetu prema migracijskom obilježju: slučaj Grada Zagreba

Ivan Čipin
{"title":"Razlike u kohortnom fertilitetu prema migracijskom obilježju: slučaj Grada Zagreba","authors":"Ivan Čipin","doi":"10.11567/met.38.1.1","DOIUrl":null,"url":null,"abstract":"The impact of migration on fertility is becoming an increasingly common research theme within the framework of population studies. Numerous demographic and geographical studies have found lower fertility in urban than in rural areas, both in developing and developed countries. Structural and contextual factors most often explain this difference. Structural factors refer to people of dissimilar socio-economic characteristics living in different areas, while contextual factors cover the current living conditions in the broadest sense. However, when explaining the urban–rural fertility differences, the selectivity of migration should also be considered, as people who (currently) have no fertility plans prefer to move to large cities. Most studies that measured fertility levels by migrant characteristics have relied on period fertility rates, while only a few have investigated cohort fertility. This study explores the cohort fertility of females by migrant status in the City of Zagreb, the largest urban centre in Croatia. Therefore, the aim is to better understand the relationship between completed fertility and migration in an urban context. Within a country, areas with the lowest fertility are often capital cities with highly educated and highly mobile populations. Although the fertility of international mi¬grants attracts more attention than internal migration, studying the association between fertility and both types of migration is especially important in a capital city with relatively high rates of inward migration. How much is known about the repro¬ductive behaviour of inward migrants in Zagreb? Are there significant differences between their fertility patterns and the patterns of native women? This paper fills this gap in the Croatian demographic literature by comparing fertility differences by migrant status across cohorts. The analysis is based on the 2011 Census data for the City of Zagreb. The Central Bureau of Statistics created a multidimensional table based on the data from this census, which includes the following variables for the female population of the City of Zagreb aged 15 or over: year of birth, number of liveborn children, highest completed education and place of birth. For analytical purposes, the data were aggre¬gated into eight five-year cohorts, with the oldest cohort born in 1930–1934 and the youngest in 1965–1969. Fertility is measured as the completed number of liveborn children per woman, which corresponds to the cohort fertility rate (CFR). The calculations are based on the standard analytical procedures used in cohort fertility analysis with census data or reproductive histories from surveys. Women are classified into four categories by migrant type: born in the City of Zagreb (native population), born in another city or another municipality in the Republic of Croatia (internal migrants), born in Bosnia and Herzegovina (external migrants – B&H), born abroad other than Bosnia and Herzegovina (external migrants – others). The 2011 census data on the number of live births are retrospective and based on the census question asking for the number of children a woman has ever had, including children who were no longer alive at the time of the census. The analysis is restricted to women born from 1930 (aged 80–81 at the time of the census) to 1969 (aged 41–42 at the time of the census), as younger women may have (more) children, while the fertility of women over 80 may be biased due to mortality and non-reporting of de¬ceased children. The analysis has shown significant differences in cohort fertility in the City of Zagreb by women’s place of birth. In all cohorts, the lowest completed fertility was achieved by women who were born in the City of Zagreb and (most likely) had no migration experience. In older cohorts, the highest fertility was recorded among women born in Bosnia and Herzegovina. In younger cohorts, fertility was highest for women born in other countries abroad. The substantial difference in completed fertility between older cohorts born in Bosnia and Herzegovina and those born in the City of Zagreb is not surprising, given that considerable differences in cohort fertility were observed between the equivalent cohorts in Croatia and Bosnia and Herzegovina. The comparison between cohort fertility rates in the City of Zagreb and Croatia shows that the cohort fertility rate in the City of Zagreb is about 0.25 (in younger co¬horts) and about 0.5 (in older cohorts) lower than in Croatia as a whole. The completed fertility of Zagreb-born women and those born elsewhere in Croatia slowly grew from older to younger cohorts (except for the youngest one). A similar trend, with some fluctuations, was observed for cohort fertility of women born abroad other than Bosnia and Herzegovina. On the other hand, completed fertility for the cohorts born in Bosnia and Herzegovina shows the opposite intercohort trend, with a notice¬able decline from the oldest to the youngest cohorts. Nevertheless, the overall cohort fertility trend is equal to that for the cohorts born in the City of Zagreb and the cohort of in-migrants from other cities/municipalities in Croatia. The share of childless women in the analysed City of Zagreb cohorts ranged from 11% to 15%, except for the youngest cohort (19%). The proportion of women who had only one child decreased from a relatively high 38% in the oldest cohort to 22– 23% in the cohorts born during the 1960s. The share of women of low parity (parities 0 and 1) decreased over time. While they represented a clear majority in the cohorts born in the 1930s, they account for below 40% in those born from 1945 to 1964. In these cohorts, in the City of Zagreb, the model of two-children families was prevalent, which is not surprising as in most post-socialist countries, having two children was a standard at the time. Women born in Bosnia and Herzegovina had lower childlessness rates than the other three categories. Women from the native cohort, especially older ones, have a rela¬tively high proportion of parity 1, while among women born in Bosnia and Herze¬govina, parity 1 is relatively low. There were no major differences in parity 2 among the analysed cohorts, with a slightly higher proportion of the two-children norm among women born in Croatia and somewhat lower in cohorts born abroad. This is expected because approximately half of the women born in the City of Zagreb in older cohorts no longer participated in reproduction after the first birth. On the other hand, women with higher parities (3 and 4+) dominate among women born in Bosnia and Herzegovina in older cohorts and among women born elsewhere abroad in the youngest cohorts. This is due to their relatively high progression to the third child (parity progression ratio 2→3 rose from 0.45 to 0.6). Interestingly, younger cohorts of women born in the City of Zagreb and the rest of Croatia are more represented in higher parities than the older cohorts. A possible explanation lies in the potentially disproportionately more significant impact of the second generation of the immigrant population whose parents were born abroad, but we should not ig¬nore numerous other economic, institutional and cultural factors of migrant fertility. In the City of Zagreb, the number and share of women with primary education has decreased, while the number and share of women with secondary and higher levels of education has increased. However, cohort fertility for all three educational groups has increased over time, with a slight decline in the youngest cohort among women with medium and high education. Probably due to the previous selectivity among the highly educated, the oldest cohort recorded a very low rate of completed fertility (about 1.1). The analysis has shown that the reproductive behaviour of in-migrants in the City of Zagreb differs from that of the native female population, depending on the place of origin. The difference between internal migrant women is minor – on average less than 0.1 children, with a convergence in the cohort fertility of younger cohorts. At the same time, the cohort fertility of women born abroad is significantly higher than of women born in Zagreb, on average by one child in older cohorts of women born in Bosnia and Herzegovina and by 0.5 children in younger cohorts born in other countries. Moving to the largest city in the country is apparently associated with lower fertility due to adaptation to high competition in the sphere of economic life on the one hand, and low urban reproductive norms on the other. The role of selective migration and the fact that individuals and couples who do not plan to have children disproportionately move to the largest urban centres should not be ignored either.","PeriodicalId":259479,"journal":{"name":"Migracijske i etničke teme / Migration and Ethnic Themes","volume":"43 3 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Migracijske i etničke teme / Migration and Ethnic Themes","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.11567/met.38.1.1","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

The impact of migration on fertility is becoming an increasingly common research theme within the framework of population studies. Numerous demographic and geographical studies have found lower fertility in urban than in rural areas, both in developing and developed countries. Structural and contextual factors most often explain this difference. Structural factors refer to people of dissimilar socio-economic characteristics living in different areas, while contextual factors cover the current living conditions in the broadest sense. However, when explaining the urban–rural fertility differences, the selectivity of migration should also be considered, as people who (currently) have no fertility plans prefer to move to large cities. Most studies that measured fertility levels by migrant characteristics have relied on period fertility rates, while only a few have investigated cohort fertility. This study explores the cohort fertility of females by migrant status in the City of Zagreb, the largest urban centre in Croatia. Therefore, the aim is to better understand the relationship between completed fertility and migration in an urban context. Within a country, areas with the lowest fertility are often capital cities with highly educated and highly mobile populations. Although the fertility of international mi¬grants attracts more attention than internal migration, studying the association between fertility and both types of migration is especially important in a capital city with relatively high rates of inward migration. How much is known about the repro¬ductive behaviour of inward migrants in Zagreb? Are there significant differences between their fertility patterns and the patterns of native women? This paper fills this gap in the Croatian demographic literature by comparing fertility differences by migrant status across cohorts. The analysis is based on the 2011 Census data for the City of Zagreb. The Central Bureau of Statistics created a multidimensional table based on the data from this census, which includes the following variables for the female population of the City of Zagreb aged 15 or over: year of birth, number of liveborn children, highest completed education and place of birth. For analytical purposes, the data were aggre¬gated into eight five-year cohorts, with the oldest cohort born in 1930–1934 and the youngest in 1965–1969. Fertility is measured as the completed number of liveborn children per woman, which corresponds to the cohort fertility rate (CFR). The calculations are based on the standard analytical procedures used in cohort fertility analysis with census data or reproductive histories from surveys. Women are classified into four categories by migrant type: born in the City of Zagreb (native population), born in another city or another municipality in the Republic of Croatia (internal migrants), born in Bosnia and Herzegovina (external migrants – B&H), born abroad other than Bosnia and Herzegovina (external migrants – others). The 2011 census data on the number of live births are retrospective and based on the census question asking for the number of children a woman has ever had, including children who were no longer alive at the time of the census. The analysis is restricted to women born from 1930 (aged 80–81 at the time of the census) to 1969 (aged 41–42 at the time of the census), as younger women may have (more) children, while the fertility of women over 80 may be biased due to mortality and non-reporting of de¬ceased children. The analysis has shown significant differences in cohort fertility in the City of Zagreb by women’s place of birth. In all cohorts, the lowest completed fertility was achieved by women who were born in the City of Zagreb and (most likely) had no migration experience. In older cohorts, the highest fertility was recorded among women born in Bosnia and Herzegovina. In younger cohorts, fertility was highest for women born in other countries abroad. The substantial difference in completed fertility between older cohorts born in Bosnia and Herzegovina and those born in the City of Zagreb is not surprising, given that considerable differences in cohort fertility were observed between the equivalent cohorts in Croatia and Bosnia and Herzegovina. The comparison between cohort fertility rates in the City of Zagreb and Croatia shows that the cohort fertility rate in the City of Zagreb is about 0.25 (in younger co¬horts) and about 0.5 (in older cohorts) lower than in Croatia as a whole. The completed fertility of Zagreb-born women and those born elsewhere in Croatia slowly grew from older to younger cohorts (except for the youngest one). A similar trend, with some fluctuations, was observed for cohort fertility of women born abroad other than Bosnia and Herzegovina. On the other hand, completed fertility for the cohorts born in Bosnia and Herzegovina shows the opposite intercohort trend, with a notice¬able decline from the oldest to the youngest cohorts. Nevertheless, the overall cohort fertility trend is equal to that for the cohorts born in the City of Zagreb and the cohort of in-migrants from other cities/municipalities in Croatia. The share of childless women in the analysed City of Zagreb cohorts ranged from 11% to 15%, except for the youngest cohort (19%). The proportion of women who had only one child decreased from a relatively high 38% in the oldest cohort to 22– 23% in the cohorts born during the 1960s. The share of women of low parity (parities 0 and 1) decreased over time. While they represented a clear majority in the cohorts born in the 1930s, they account for below 40% in those born from 1945 to 1964. In these cohorts, in the City of Zagreb, the model of two-children families was prevalent, which is not surprising as in most post-socialist countries, having two children was a standard at the time. Women born in Bosnia and Herzegovina had lower childlessness rates than the other three categories. Women from the native cohort, especially older ones, have a rela¬tively high proportion of parity 1, while among women born in Bosnia and Herze¬govina, parity 1 is relatively low. There were no major differences in parity 2 among the analysed cohorts, with a slightly higher proportion of the two-children norm among women born in Croatia and somewhat lower in cohorts born abroad. This is expected because approximately half of the women born in the City of Zagreb in older cohorts no longer participated in reproduction after the first birth. On the other hand, women with higher parities (3 and 4+) dominate among women born in Bosnia and Herzegovina in older cohorts and among women born elsewhere abroad in the youngest cohorts. This is due to their relatively high progression to the third child (parity progression ratio 2→3 rose from 0.45 to 0.6). Interestingly, younger cohorts of women born in the City of Zagreb and the rest of Croatia are more represented in higher parities than the older cohorts. A possible explanation lies in the potentially disproportionately more significant impact of the second generation of the immigrant population whose parents were born abroad, but we should not ig¬nore numerous other economic, institutional and cultural factors of migrant fertility. In the City of Zagreb, the number and share of women with primary education has decreased, while the number and share of women with secondary and higher levels of education has increased. However, cohort fertility for all three educational groups has increased over time, with a slight decline in the youngest cohort among women with medium and high education. Probably due to the previous selectivity among the highly educated, the oldest cohort recorded a very low rate of completed fertility (about 1.1). The analysis has shown that the reproductive behaviour of in-migrants in the City of Zagreb differs from that of the native female population, depending on the place of origin. The difference between internal migrant women is minor – on average less than 0.1 children, with a convergence in the cohort fertility of younger cohorts. At the same time, the cohort fertility of women born abroad is significantly higher than of women born in Zagreb, on average by one child in older cohorts of women born in Bosnia and Herzegovina and by 0.5 children in younger cohorts born in other countries. Moving to the largest city in the country is apparently associated with lower fertility due to adaptation to high competition in the sphere of economic life on the one hand, and low urban reproductive norms on the other. The role of selective migration and the fact that individuals and couples who do not plan to have children disproportionately move to the largest urban centres should not be ignored either.
移徙对生育率的影响正在成为人口研究框架内日益普遍的研究主题。许多人口和地理研究发现,在发展中国家和发达国家,城市生育率低于农村地区。结构和语境因素最常解释这种差异。结构性因素是指生活在不同地区的具有不同社会经济特征的人,而背景因素则是指最广泛意义上的当前生活状况。然而,在解释城乡生育率差异时,还应考虑到人口迁移的选择性,因为(目前)没有生育计划的人更倾向于迁移到大城市。大多数通过移民特征衡量生育水平的研究都依赖于时期生育率,而只有少数研究了群体生育率。本研究探讨了克罗地亚最大的城市中心萨格勒布市不同移民身份的女性群体生育率。因此,目的是更好地了解在城市背景下已完成的生育率与人口迁移之间的关系。在一个国家内,生育率最低的地区往往是人口受教育程度高、流动性强的首都城市。虽然国际移民的生育率比国内移民更受关注,但研究生育率与这两种移民之间的关系,在一个向内移民率相对较高的首都尤为重要。我们对萨格勒布外来移民的生殖行为了解多少?她们的生育模式与当地妇女的生育模式有显著差异吗?本文填补了克罗地亚人口统计文献中的这一空白,通过比较跨队列移民身份的生育率差异。该分析基于萨格勒布市2011年的人口普查数据。中央统计局根据这次普查的数据制作了一个多维表格,其中包括萨格勒布市15岁及以上女性人口的以下变量:出生年份、活产儿童人数、最高受教育程度和出生地点。为了便于分析,研究人员将数据汇总为8个5年的队列,其中年龄最大的队列出生于1930-1934年,年龄最小的队列出生于1965-1969年。生育率是以每名妇女活产子女的总数来衡量的,这与队列生育率(CFR)相对应。这些计算是根据人口普查数据或来自调查的生育史的队列生育分析中使用的标准分析程序进行的。妇女按移民类型分为四类:出生在萨格勒布市(本地人口)、出生在克罗地亚共和国另一个城市或另一个直辖市(国内移民)、出生在波斯尼亚和黑塞哥维那(外来移民- B&H)、出生在波斯尼亚和黑塞哥维那以外的国外(外来移民-其他)。2011年人口普查关于活产婴儿数量的数据是回顾性的,并基于人口普查问题,即一名妇女曾经生育过的孩子数量,包括在人口普查时已经去世的孩子。该分析仅限于1930年(人口普查时年龄在80 - 81岁之间)至1969年(人口普查时年龄在41-42岁之间)出生的妇女,因为年轻妇女可能有(更多)孩子,而80岁以上妇女的生育率可能因死亡率和未报告死亡儿童而存在偏差。分析显示,萨格勒布市妇女的出生地在队列生育率方面存在显著差异。在所有队列中,出生在萨格勒布市且(很可能)没有移民经历的妇女的完成生育率最低。在年龄较大的人群中,在波斯尼亚和黑塞哥维那出生的妇女生育率最高。在更年轻的人群中,在国外其他国家出生的女性生育率最高。出生在波斯尼亚和黑塞哥维那的老年群体与出生在萨格勒布市的老年群体在完全生育率方面的巨大差异并不令人惊讶,因为在克罗地亚和波斯尼亚和黑塞哥维那的同等群体之间观察到队列生育率的巨大差异。萨格勒布市和克罗地亚队列生育率的比较表明,萨格勒布市的队列生育率(年轻队列)约为0.25,(老年队列)约为0.5,低于克罗地亚整体水平。出生在萨格勒布的妇女和出生在克罗地亚其他地方的妇女的完整生育率从年龄较大的人群缓慢地向年轻人群增长(最年轻的人群除外)。在波斯尼亚和黑塞哥维那以外的其他国家出生的妇女的群体生育率也出现了类似的趋势,但有一些波动。另一方面,在波斯尼亚和黑塞哥维那出生的队列的完整生育率显示出相反的队列间趋势,从最老的队列到最年轻的队列明显下降。 然而,整个队列生育率趋势与在萨格勒布市出生的队列和从克罗地亚其他城市/市迁入的队列的生育率趋势相同。在分析的萨格勒布市队列中,无子女妇女的比例从11%到15%不等,除了最年轻的队列(19%)。只有一个孩子的妇女比例从年龄最大的队列中相对较高的38%下降到20世纪60年代出生的队列中的22.23%。低胎次(第0胎次和第1胎次)的妇女所占比例随着时间的推移而下降。虽然他们在20世纪30年代出生的人群中占明显多数,但在1945年至1964年出生的人群中,他们的比例不到40%。在萨格勒布市的这些人群中,两个孩子的家庭模式很普遍,这并不奇怪,因为在大多数后社会主义国家,有两个孩子是当时的标准。在波斯尼亚和黑塞哥维那出生的妇女的无子女率低于其他三类妇女。来自本国的妇女,特别是年龄较大的妇女的胎率相对较高,而在波斯尼亚-黑塞哥维那出生的妇女中,胎率相对较低。在被分析的队列中,胎次没有重大差异,在克罗地亚出生的女性中,生育两个孩子的比例略高,而在国外出生的女性中,生育两个孩子的比例略低。这是预料之中的,因为在萨格勒布市出生的老年妇女中,大约有一半在第一次生育后不再参加生育。另一方面,较高胎次(3胎和4胎以上)的妇女在波斯尼亚和黑塞哥维那出生的妇女中占主导地位,在国外其他地方出生的妇女中占主导地位。这是由于他们相对较高的进度到第三个孩子(胎次进度比2→3从0.45上升到0.6)。有趣的是,出生在萨格勒布市和克罗地亚其他地区的年轻女性在更高的政党中比年龄较大的女性更有代表性。一种可能的解释是,父母出生在国外的第二代移民人口可能产生不成比例的更大影响,但我们不应忽视影响移民生育率的众多其他经济、制度和文化因素。在萨格勒布市,接受初等教育的妇女人数和比例有所下降,而接受中等及以上教育的妇女人数和比例有所增加。然而,随着时间的推移,所有三个受教育群体的群体生育率都有所上升,受过中等和高等教育的女性中最年轻的群体生育率略有下降。可能是由于先前对受过高等教育的人的选择性,最年长的队列记录的完成生育率非常低(约为1.1)。分析表明,萨格勒布市内移徙者的生殖行为与当地女性人口的生殖行为不同,这取决于原籍地。国内移民妇女之间的差异很小——平均不到0.1个孩子,年轻群体的群体生育率趋于一致。与此同时,在国外出生的妇女的群体生育率明显高于在萨格勒布出生的妇女,在波斯尼亚和黑塞哥维那出生的老年妇女群体中平均多生一个孩子,在其他国家出生的年轻妇女群体中平均多生0.5个孩子。搬到这个国家最大的城市显然与低生育率有关,一方面是由于适应了经济生活领域的高竞争,另一方面是城市的低生育标准。选择性移民的作用以及不打算生育的个人和夫妇不成比例地迁移到最大的城市中心的事实也不应被忽视。 然而,整个队列生育率趋势与在萨格勒布市出生的队列和从克罗地亚其他城市/市迁入的队列的生育率趋势相同。在分析的萨格勒布市队列中,无子女妇女的比例从11%到15%不等,除了最年轻的队列(19%)。只有一个孩子的妇女比例从年龄最大的队列中相对较高的38%下降到20世纪60年代出生的队列中的22.23%。低胎次(第0胎次和第1胎次)的妇女所占比例随着时间的推移而下降。虽然他们在20世纪30年代出生的人群中占明显多数,但在1945年至1964年出生的人群中,他们的比例不到40%。在萨格勒布市的这些人群中,两个孩子的家庭模式很普遍,这并不奇怪,因为在大多数后社会主义国家,有两个孩子是当时的标准。在波斯尼亚和黑塞哥维那出生的妇女的无子女率低于其他三类妇女。来自本国的妇女,特别是年龄较大的妇女的胎率相对较高,而在波斯尼亚-黑塞哥维那出生的妇女中,胎率相对较低。在被分析的队列中,胎次没有重大差异,在克罗地亚出生的女性中,生育两个孩子的比例略高,而在国外出生的女性中,生育两个孩子的比例略低。这是预料之中的,因为在萨格勒布市出生的老年妇女中,大约有一半在第一次生育后不再参加生育。另一方面,较高胎次(3胎和4胎以上)的妇女在波斯尼亚和黑塞哥维那出生的妇女中占主导地位,在国外其他地方出生的妇女中占主导地位。这是由于他们相对较高的进度到第三个孩子(胎次进度比2→3从0.45上升到0.6)。有趣的是,出生在萨格勒布市和克罗地亚其他地区的年轻女性在更高的政党中比年龄较大的女性更有代表性。一种可能的解释是,父母出生在国外的第二代移民人口可能产生不成比例的更大影响,但我们不应忽视影响移民生育率的众多其他经济、制度和文化因素。在萨格勒布市,接受初等教育的妇女人数和比例有所下降,而接受中等及以上教育的妇女人数和比例有所增加。然而,随着时间的推移,所有三个受教育群体的群体生育率都有所上升,受过中等和高等教育的女性中最年轻的群体生育率略有下降。可能是由于先前对受过高等教育的人的选择性,最年长的队列记录的完成生育率非常低(约为1.1)。分析表明,萨格勒布市内移徙者的生殖行为与当地女性人口的生殖行为不同,这取决于原籍地。国内移民妇女之间的差异很小——平均不到0.1个孩子,年轻群体的群体生育率趋于一致。与此同时,在国外出生的妇女的群体生育率明显高于在萨格勒布出生的妇女,在波斯尼亚和黑塞哥维那出生的老年妇女群体中平均多生一个孩子,在其他国家出生的年轻妇女群体中平均多生0.5个孩子。搬到这个国家最大的城市显然与低生育率有关,一方面是由于适应了经济生活领域的高竞争,另一方面是城市的低生育标准。选择性移民的作用以及不打算生育的个人和夫妇不成比例地迁移到最大的城市中心的事实也不应被忽视。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信